A leading online university hosts an intranet that employees access to do most of their work. Consequently, if performance drops, so does productivity. When its intranet databases began to slow, it tasked its lead systems engineer with finding a solution.

The university’s initial intranet infrastructure consisted of four MySQL database servers that supported three application servers. These application servers hosted multiple productivity applications. As the system team began investigating application and database slowness, it became evident right away that disk latency was the primary performance problem.

The Solution

The lead systems engineer had been watching SanDisk for years and was confident its Fusion ioMemory ioDrive® cards could solve the university’s problems. After evaluating several options, he and his team agreed that SanDisk was the best solution to resolve the university’s disk latency issues.

Running the Benchmarks
The university ran benchmark tests comparing eight 15K RPM SAS drives configured in a RAID 10 to one ioDrive® Duo card with its two DIMMs striped in a RAID 0.

This table shows the benchmark results, reported in megabinary bits (MiB) of 1024k (higher is better).

8 x 15k Disk Array

ioDrive Duo

MiB/sec

Random Reads

150

1,006

Random Writes

272

626

IOPS

Random Reads

3,548

110,000

Random Writes

3,517

145,000

Improving Queries
The week before it deployed the ioDrive cards into production, the database team had run a long query that took 2 1/2 hours to complete. On a whim, the engineers asked a DBA to run the same query again on the ioDrive system. They then left for an hour-long meeting, hoping the query would be done by the time the meeting ended. Five minutes later, before the meeting even started, the DBA called saying, “It’s done. What’s the next test?”

“Since implementing the ioDrive cards, query performance has ceased to be a problem. Our DBAs still tune queries, of course. But from a system engineer’s standpoint, I no longer have any reason to ask them to.” said the lead engineer.

Speeding Replication
In the previous system, the replication lag between the master and read servers often resulted in stale data. To end users, it could appear as if updates hadn’t occurred, resulting in support tickets that were “magically” fixed by the time the support team investigated and replication had caught up. The ioDrive system replicated the largest transactions in mere seconds instead of minutes, completely eliminating this problem.

Eliminating Performance Complaints
The university deployed the SanDisk powered system over the holidays, immediately putting the ioDrive cards’ scalability to the test, as January is the university’s busiest time of the year. Typically, this spike in activity severely taxed the system and presented support a corresponding increase in performance-related complaints. However, the SanDisk powered system handled the spikes without any noticeable impact on performance.

For once, support wasn’t fielding performance tickets, and employees were able to focus on doing their work instead of waiting on applications.

“Since deploying the ioDrive cards, our support team hasn’t received a single support ticket related to the intranet application and database performance,” the lead engineer told us. “That, to me, is the most important benchmark of all.”

“Since deploying the ioDrive cards our support team hasn’t received a single support ticket related to the intranet application and database performance. That, to me, is the most important benchmark of all.”

Lead Systems Engineer
Online University

A Simple and Elegant Architecture
With recommendations from SanDisk’s expert field engineers, the university’s system team devised an architecture that eliminated key I/O and CPU bottlenecks, while actually simplifying its system.

The new database layer replaced the four database servers with just two new Hewlett-Packard DL380 servers, each equipped with a 640GB ioDrive card.

Initially, the lack of infrastructure caused some concern about reliability, as management had come to equate adding hardware with reliability. However, the lead engineer pointed out several strengths of the SanDisk powered system. First, the ioDrive cards didn’t have the additional data hand-offs between controllers, RAM caches, and between the host and storage media, each of which could compromise integrity. Second, the new system had a much simpler outage scenario now that it consisted of two servers instead of four. If the master server failed, the SanDisk system’s replication allowed the read server to change to a fully functioning master much faster, reducing the risk of data loss. Like the previous system, the new master server maintained a read pool that allowed it to serve as both master and read if the read server failed, without disruption in service.

In addition to the advantages ioDrive cards had over the previous system, the engineer noted the data integrity advantages inherent in ioDrive cards. He told us, “With the Fusion ioMemory product, I know my data is protected. The capacitors on the SanDisk cards will never die, and I’ll never have to perform maintenance.”

Thus, with half the servers, the system team got both a more powerful database layer and a more reliable one.

Enabling Efficient Asset Use
The ioDrive cards’ performance eliminated I/O bottlenecks in the university’s database. However, this newfound performance exposed another bottleneck – the university’s applications were CPU-bound. But this ended up being a non-issue since the ioDrive card purchase had freed up four servers, the systems team was able to repurpose these as application servers to redistribute the CPU load and further improve application performance.

ROI on Steroids
One of the most compelling aspects of the SanDisk solution was its return on investment (ROI).

First, the university repurposed four database servers as application servers, eliminating the need for new hardware purchases while also improving application performance.

Second, the SanDisk powered systems have CPU capacity to spare. The lead engineer told us the databases only use an average of 20% of their processing power, so he doesn’t expect the university will need to upgrade the database servers again during the life of the ioDrive cards.

Third, the university cut the database layer’s hardware and software administration overhead by half.

Finally, the university eliminated the floor space, power, and cooling costs of the additional servers.

Evaluating Competing Solutions
While making its purchase decision, the systems team evaluated several solutions against a 100,000 IOPS performance threshold.

The team ruled out SANs almost immediately since, as the lead engineer put it, “It would have taken hundreds of disks to equal the performance of just one ioDrive card.”

The lead engineer told us, “There wasn’t enough space in a single server to get 100,000 IOPS and by the time we aggregated everything, the Fusion ioMemory solution came out cheaper. Additionally, we would have had to purchase multiple RAID controllers with failure groups and a hot spare. The complexity and expense of other options made SanDisk a no-brainer.”

Competing PCI Express SSDs were also ruled out for two reasons. First, as described above, the reliability issues created a concern. Second, these solutions cost much more for equivalent performance.

System Before

MySQL 5.x on Mac Xserve Cluster

Four Apple servers

Eight 15K RPM SAS drives

System After

Changes to the System

Replaced the four Apple servers with two new HP DL380 x550 processors and two 640GB ioDrives

Repurposed two of the four database servers as application servers

Performance per Rack Unit (Density)

With SanDisk

5 minutes

Without SanDisk

150 minutes

30x

Improvement

Query processing reduced from 150 minutes to 5 minutes, delivering 30 times the performance in the same rack space.

Summary

Implementing the Fusion ioMemory solution gave the university the following benefits:

30x faster queries

Replication reduced from minutes to seconds, ensuring end users get the most up-to-date data

Completely eliminated complaints and support tickets about intranet performance